Jetboil shook up the stove world a few years back with its revolutionary namesake stove. The little one-pound stove always knew it wanted its own handle, so after working as a runner, sucking on a 40 down at the corner and yelling "five-oh" it finally proved itself and was awarded a street name: the Flash!
The original Jetboil was a great design, and the Flash wisely keeps all that worked and makes some small but real improvements. If only all products evolved this way! The 1L cup with integrated heat exchanger is pretty much the same, but the neoprene insulator has been updated with a fancy little three-stripe thingie that turns orange when the contents are about to boil. At first it seemed kind of gimmicky, but it was cool to be ten feet away from the Flash and be able to see at a glance when it actually needed attention. More useful is the little tab for holding utensils.
There's nothing gimmicky about the performance. The Flash still cranks up hot water in no time at above-freezing temps. Even down towards single digits Fahrenheit it did a respectable job, bringing water to a boil in about five minutes (Jetboil makes another stove for colder temps). The reliable push-button ignitor is new and improved, as is the burner, and best of all the temperature control knob now has a flip-out wire bail that can be used easily with gloves on. The bottom plastic cup removes easier as well, and the stove base, fuel canister and very cool new included folding tripod base all conveniently stow inside the cup with room to spare. The tripod has notches for two sizes of canister and provides a very stable base; you can pick the whole thing up while it's burning and move it easily. Bottom line: a fantastic three-season canister stove.